What was found
FLT NR 954 - ROR - WITH NR 1 ENGINE GENERATOR ALREADY ON MEL DEFERAL, AFTER AIRCRAFT DEPARTURE OUT OF ROR, NR 2 GENERATOR TRIPPED AND UNABLE TO RESET, PERFORMED APPROPRIATE ABNORMAL CHECKLIST. AIRCRAFT DIVERTED BACK TO ROR. MAINTENANCE TROUBLESHOT AND FOUND NR 2 GENERATOR CONTROL PANEL WAS AT FAULT. DUE TO PARTS NOT AVAILABLE, SWAPPED NR 1 GCU WITH NR 2 GCU MFG P/N 902F242-5 S/N ON NR 1 5742, ON NR 2 2966. ALL SYSTEMS CHECKS GOOD AND AIRCRAFT RETURN BACK IN SERVICE. AFTER ARRIVAL GUAM, MAINTENANCE REPLACED NR 1 GENERATOR CSD ASSY MFG P/N 700842A S/N OFF 0880 ON 9236. PRECAUTIONARY REPLACED NR 2 GENERATOR ASSY, MFG P/N 976J498-1 S/N OFF 7566 ON 6168. ALL SYSTEM CHECKS GOOD. (W)